Glide assembly

ABSTRACT

An assembly for aiding self-locomotion of a wearer of leg cast or other foot immobilizing device whereby a selective sliding motion may be utilized in place of the conventional walking motion. The assembly includes a resilient retainer having apertures into which inserts of a low coefficient of friction, which protrude slightly above the retainer, are placed. Engagement of the retainer with the surface over which locomotion is to be effected permits a sliding of the limb; however, when a predetermined weight is applied to the assembly, the resiliency of the retainer allows the inserts to be pressed inwardly into their aperture such that the surrounding retainer provides a nonslip, frictional engagement with said surface. Alternatively, each insert could have its own resilient support mounted within its aperture to allow for the relative movement between it and the retainer.

United States Patent 3,744,487 [4 1 July 10,1973

Lipson et al.

[ GLIDE ASSEMBLY 22 Filed: Nov. 10,1971 211 Appl.No.: 197,428

Related US. Application Data [63] Continuation-impart of Ser. No.848,295, Aug. 7,

1969, Pat. No. 3,633,573.

Primary ExaminerRichard A. Gaudet Assistant Examiner-J. YaskoAtt0rneyHarry A. Herbert, Jr. et al.

[5 7] ABSTRACT An assembly for aiding self-locomotion of a wearer of legcast or other foot immobilizing device whereby a selective slidingmotion may be utilized in place of the conventional walking motion. Theassembly includes a resilient retainer having apertures into whichinserts of a low coefficient of friction, which protrude slightly abovethe retainer, are placed. Engagement of the retainer with thesurfaceover which locomotion is to be effected permits a sliding of the limb;however, when a predetermined weight is applied to the assembly, theresiliency of the retainer allows the inserts to be pressed inwardlyinto their aperture such that the surrounding retainer provides anon-slip, frictional engagement with said surface. Alternatively, eachinsert could have its own resilient-support mounted within its apertureto allow for the relative movement between it and the retainer.

6 Claims, 8 Drawing Figures 1 GLIDE ASSEMBLY BACKGROUND OF THE INVENTIONThis is a continuation-in-part of application Ser. No. 848,295 filedAug. 7, 1969 now U.S. Pat. No. 3,633,573.

This invention relates to an assembly for permitting the wearer of awalking-type cast, or of an orthopedic shoe, or the like, selectively toslideably engage his encased foot with the floor and, thereby, allow himeasier locomotion. More particularly, the invention relates to anassembly which includes glide inserts of low coeffi cient of frictionmaterial which are inserted into, and are removable from, apertures in aresilient retainer of high coefficient of friction material, with theassembly adaptable for use as the heel assembly or sole assembly affixedto the foot-bottom of a walking-type leg cast, or as the principalcomponent of an orthopedic shoe, and the like.

It is to be noted that the terms walking-type leg cast, walking legeast, walking cast," and cast as used above and as hereinafter used, areintended, for the purpose of this application, to be synonymous andinterchangeable, and are also intended to include a foot cast, an anklecast, and the like. What is meant by use of any of the above terms ortheir equivalents is that at least the foot, but not necessarily thetoes, is immobilized in a conventional plaster cast having, in whole orin part, a base or bottom serving as a sole.

In the prior art, individuals having a cast-bound foot moved under theirown power by lifting the foot up and then lowering it, in a walkingmotion, thereby placing their full weight on the foot and the cast.Alternatively, they used canes and crutches of various modified forms toassist them in moving under their own power. In

doing so, they favored the encased foot by placing all or most of theirweight on the other foot and on the cane or crutches used, withresultant strain on the other foot, on the hand grasping the cane, and,in using crutches, on the hands grasping the crutch, the arms, and thearmpits.

The art advanced substantially with the advent and the use of afloor-engageable peg at the foot-bottom of the cast, since the user ofsuch a walking cast could walk in many instances without the use ofcanes or crutches, by lifting and then lowering his foot, with theweight being placed on the peg. However, despite the availability anduse of canes, crutches, floorengageable pegs, and other prior andpresent art devices, the individual who sustains a foot, ankle or legbreak or fracture which allows or requires a walkingtype cast is, atbest, in the unfortunate position of being able to move under his ownpower only with strain, resultant fatigue, great inconvenience, and somelack of safety, with the degree of these distinct disadvantagesincreasing with the length and weight of the cast.

Our invention significantly advances the state-of-theart by permittingindividuals who have a cast-bound foot to move with a sliding motion,rather than'a walking motion, with the sliding being much easier, lessawkward, less fatiguing, and relatively safer than walking; and, inaddition, our invention promotes recovery, principally by minimizingweight-bearing on the castbound foot, and thereby permits the earlierreturn of the individual to his normal activities. When weight isapplied to the structure of our invention, a conventional frictionsurface is provided to inhibit sliding and provide stability. Thus, anundesired rotation is not necessary to engage the frictional surfacewith the floor.

- SUMMARY OF THE INVENTION under his own power by selectively slidinghis encased foot along the floor and enabling a frictional engagementwith the floor, when desired, without a rotation of the foot.

Another object of this invention is to permit the individual toaccomplish the above-described selflocomotion with much more ease, muchless fatigue, andin the relatively safer manner thanis possible withpast or present state-of-the-art devices.

These objects, and still other and related ones, of this invention willbecome readily apparent after a consideration of the description of theinvention and reference to the drawings.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation view, partly incross-section, of a preferred embodiment of the invention;

FIG. 2 is the bottom view of another preferred embodiment of theinvention;

FIG. 3 is a side elevation view, in cross-section, of the embodimentshown in FIG. 2;

FIG. 4 is the bottom view of still another preferred embodiment of theinvention;

FIG. 5 is a side elevation view, in cross-section, of the embodimentshown in FIG. 4;

FIG. 6 is the bottom view of yet another preferred embodiment of theinvention;

FIG. 7 is a side elevation view, partly in cross-section, of theembodiment shown in FIG. 6; and

FIG. 8 is a side elevation view, in cross-section, of alternativepreferred embodiments of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to FIG. 1, thereis shown, in side elevation and partly in cross-section a preferredembodiment in the form of a heel assembly 10 which includes afloor-.engageable glide insert 11 of material having a low coefficientof friction (.i.e., having good sliding properties), such as a durableplastic material which additionally can be easily fabricated and molded,preferably nylon or teflon, with said glide insert 11 securely insertedor fitted into, but'removable from, suitably configurated aperture 12 ofa resilient heel 13, which is of material of a high coefficient offriction, preferably rubber, and with said heel 13 having, if desired, aserrated or otherwise roughened base 14 and a lip or flange 15. Alsoshown therein is walking cast 16 with wall 17 and base or bottom 18. Thelower surface of lip 15 of heel assembly 10 abuts the upper surface ofcast wall 17; and heel assembly 10 is made integral to cast- 16, withheel l3 and glide insert 11 protruding slightly from the bottom of cast16. The resiliency of the heel is controlled such that upon apredetermined pressure exerted by the wearer, the glide inserts will bepressed inwardly and the high friction material will be in engagementwith the floor to inhibit sliding.

In FIGS. 2 and 3, wherein the same reference numbers designate the samecomponents, is shown another embodiment, heel assembly 20, in,respectively, a bottom view and a side elevation cross-sectional view.Heel assembly includes floor-engageable glide inserts 21 and 22 ofmaterial having a low coefficient of friction (i.e., having good slidingproperties), such as a durable plastic material which additionally canbe easily fabricated and molded, preferably nylon or teflon, with saidglide inserts 21 and 22 securely inserted into or fitted into, butremovable from any suitably configurated apertures 23 and 24,respectively, of resilient heel 25, which is of material of a highcoefficient of friction, preferably rubber, and with said heel 25having, if desired, a serrated or otherwise roughened base 26 and a lipor flange 27. Not shown, in the interest of maintaining simplicity andclarity, is the walking cast, such as 16, FIG. 1, to which heel assembly20 is made integral, with heel 25 and glide inserts 21 and 22 protrudingslightly from the bottom of the cast.

In FIGS. 4 and 5, wherein the same reference numbers designate the samecomponents, is shown still another preferred embodiment of the inventionin the form of a platform or sole assembly 30 in, respectively, a bottomview and a side elevation cross-sectional view. Sole assembly 30includes a plurality of floorengageable glide inserts, such as 31-36inclusive, of material having a low coefficient of friction (i.e.,having good sliding properties), such as a durable plastic whichadditionally can be easily fabricated and molded, preferably nylon orteflon, with each said glide insert, such as 31, FIG. 5, securelyinserted into or fitted into, but removable from, its suitablyconfigurated individual aperture, such as 37, FIG. 5, of the pluralityof apertures, such as 3742 inclusive, FIG. 4, of a resilient platform orsole 43 which is of material of a high coefficient of friction,preferably rubber, and which has lip or flange 44. Also shown in FIG. 5,in cross-section and partly fragmented, is walking cast 45, with base orbottom 46, to which sole assembly 30 is made integral by being positionwholly within said cast 45, and being affixed thereto, with the bottomsurface of sole 43 and the bottom of glide inserts, 31-36 inclusiveexposed and external of cast 45.

In FIGS. 6 and 7, wherein the same reference numbers designate the samecomponents, is shown yet another preferred embodiment of the inventionin the form of an orthopedic shoe 50, in, respectively, a bottom viewand a side elevation cross-sectional view. Orthopedic shoe includes: aresilient platform or sole 51 of material of high coefficient offriction, preferably rubber, to which is affixed by suitable means atthe periphery thereof means for permitting entry, retention, and, whendesircd,release of the cast-bound foot, such as a top 53 of flexiblematerial, preferably canvas, and laces or ties (not shown) connected tosaid top 53. Sole 51 has a plurality or apertures, such as 54-62inclusive, FIG. 6, into which are securely inserted or fitted aplurality of floor-engageable glide inserts, such as 63-71 inclusive,FIG. 6, made of material of a low coefficient of friction, such as adurable plastic which additionally can be easily fabricated and molded,preferably nylon or teflon. The guide inserts, such as 54, FIG. 7, areremovable from their suitably configurated individual apertures, such as63, FIG. 7. The upper surface of sole 51 is, preferably, raised at therear or heel portion 52.

With reference to FIGS. l-7, inclusive, glide inserts (such as 11, FIG.1; 21 and 22, FIGS. 2 and 3; 31-36 inclusive, FIGS. 4 and 5; and 63-71inclusive, FIGS. 6 and 7) are, individually, preferably in the form of acylinder of two diameters, with the narrower diameter being insertedwholly into the suitably configured aperture (such as 12, FIG. 1) andthe wider diameter protruding a short distance from the bottom of theheel (such as 14, FIG. 1, and 25, FIGS. 2 and 3) and from the bottom ofthe platform or sole (such as 43, FIGS. 4 and 5, and 51, FIGS. 6 and 7),with the bottom surface of the wider diameter portion of the glideinsert engaging and making contact with the floor. Although the glideinserts are shown in FIGS. 1-7 to be flatbottomed, this is by way ofillustration only. The bottom of the glide inserts (such as 11, FIG. 1;21 and 22, FIGS. 2 and 3; 31-36 inclusive, FIGS. 4 and 5; and 63-71inclusive, FIGS. 6 and 7, may be of any suitable shape or form,including the point-contact type. In all of the embodiments thus fardescribed the material in which the glide inserts are placed is ofsufficient resiliency, at least in the portion immediately surroundingeach insert, such that upon a predetermined pressure exerted by thewearer, the glide insert would be pressed inwardly and the highfrictional material would then be in engagement with the floor toinhibit sliding. This can be effected without a rotation of the sole andheel portions.

With reference to FIG. 8, therein is shown in a side elevationcross-sectional view still other preferred embodiments of the invention.The embodiment is a means for permitting self-locomotion by the wearerof a walking-type leg cast by a sliding movement, rather than bywalking, and includes a retainer 81 of material of a high coefficient offriction, preferably rubber, for use as a heel, platform, sole, or thelike with apertures, such as 82 and 83, having at the upper terminus,such as 84 and 85, a wider diameter to accept and hold a glide insert,such as 90, made of material of a low coefficient of friction, such as adurable plastic which additionally can be easily fabricated and molded,preferably nylon or teflon. Each glide insert, such as 90, isconfigurated in the form of a cylinder of three diameters, with the twodiameters, such as 91 and 92, being at either end and the narrowestdiameter, such as 93, being therebetween. The upper wider diameter 92 ofglide insert fits into the upper terminus, such as 84 and 85, of theaperture, such as 82 and 83. The narrowest diameter 93, which is themidportion of glide insert 90, fits into, and is positioned whollywithin, the narrow diameter of the aperture. The other wide diameterportion 91 of glide insert 90 protrudes a short distance from the bottomof retainer 81 and, thereby, engages and makes contact with the floor.It is to be noted that a glide insert, such as 90, may be removed fromthe respective aperture, such as .83, in which it is positioned,although in use the glide insert is securely fitted into and held by themating configuration of the aperture. As in the case of the glideinserts shown in FIGS. l-7, the glide insert 90, FIG. 8, need not beflat-bottomed, as shown. The bottom may be of any suitable shape orform, including the point-contact type.

The insert arrangement thus far described relative to FIG. 8 could havethe retainer 81 of resilient material as described relative to thepreviously presented embodiments or, alternatively, that portionimmediately surrounding each aperture could be of a resilient materialsuch that upon the exertion of a predetermined pressure on the assemblyby the wearer the glide inserts 90 would be pressed inwardly to enablethe sole or heel portions beyond the glides to be in frictionalengagement with a floor, thereby inhibiting sliding without requiring arocking or rotary motion of the foot to effect the frictional materialinengagement with the floor.

Although the glides have been thus far described in frictionalengagement with the apertures, it is comtemplated that, as illustratedat the right of FIG. 8, the glide 100 could be retained in an apertureas illustrated at 101 by means of a spring 102 attached to the glide byfriction, pinning or other conventional means. The spring 102 is securedin the upper, larger diameter portion by expansion into the groove at103. In this case, the controlled resiliency of the sole and heelportions would not have-to be specified since the spring wouldeffectively allow for the movement of the glide insert intothe retainerelement at 104.

Additionally, as shown in phantom with respect to glide insert 90, aball bearing 95 may be provided within the glide which forms a racktherefor. If the ball bearing were utilized, the protrusion of the glidefrom the retainer would be less so that the ball bearing only protrudesslightly from the retainer. In any case, the various types of glidecould be used in combination or means.

MODE OF OPERATIONOF THE PREFERRED EMBODIMENTS The operation of each ofthe preferred embodiments is based upon the phenomena that it is easier(i.e., less fatiguing, less awkward, and the like) for an individualhaving a cast-bound foot to slide on it, rather than to walk on it. Itis further advantageous for the wearer of one of the preferredembodiments, previously described, to avoid a rocking action of his footin order to provide engagement of the frictional container with thefloor. More specifically, in the embodiments the combination of the lowcoefficient of friction material glide inserts fitted into a retainer ofmaterial of high coefficient of friction with both, or either, of thedifferent coefficient of friction materials being simultaneouslyfloor-engageable at the option of the user, permits a controlled slidingmotion, rather than walking, which is a new and unexpected result notheretofore contemplated in the art.

Embodiments 10, FIG. 1, and 20, FIGS. 2 and 3, are affixed by and duringthe molding of the foot cast, such as 16, FIG. 1, to the bottom 18, FIG.1, of the cast 16. More specifically, the lower surface of the flangedportion, such as 15, FIG. 1, of heel 13, FIG. 1, and 27, FIGS. 2 and 3,of heel 25, FIGS. 2 and 3, is made to abut with the upper surface of thebottom 18 of cast 16, FIG. 1. Each of these two embodiments (heelassembly 10, FIG. 1, and heel assembly 20, FIGS. 2 and 3) are madeintegral to the cast, such as 16, FIG. 1, while the cast is beingmolded. The heel of each embodiment, such as 13, FIG. 1, and 25, FIGS. 2and 3, with the glide insert(s), such as 11, FIG. 1, and 21 and 22, FIG.2, in heel apertures, such as 12, FIG. 1, and 23 and 24,

FIGS. 2 and 3, is made to protrude slightly from the bottom of the cast.The specific position of the heel embodiment, such as 10, FIG.-1, and20, FIGS. 2 and 3, at the bottom 18 of the cast 16, FIG. 1, and thelocation of the heal aperture(s) with the glide insert(s), is dependentupon, and determined by, the respective position and location which willpermit easy sliding motion of the glide insert(s) and, yet, will resultin sufficient braking force from the rubber heel, such as 13, FIG. 1,with its serrated base, such as 14, FIG. 1, to stop unchecked sliding,in the unlikely event that that should occur. This is controlled byapplication of the weight of a user to the glide element tocause it toretract. The individual with a cast embodying our invention, as depictedin FIGS. 1 and 2, merely slides his cast-bound foot on the glideinsert(s), such as 11, FIG. 1, and 21 and 22, FIGS. 2 and 3, rather thanlifting and then lowering the cast-bound foot, as he would do if he wereusinga walking movement.Neverthele'ss, the individual may, should hedesire to do so, walk with the cast, rather than using the intendedsliding movement. In fact, since the glide inserts are removable forreplacement and the like, theymay be removed in a particular instance ifthe removal facilitates walking.

Embodiment 30, FIGS.- 4 and 5, which is our invention in the form ofa'platform 'or sole assembly, is inserted in the cast, such as45, FIG.5; and, as the botalone with the various embodiments of the retainingtom, such as 46, FIG. 5,01 the east is being molded to the wearers foot,the entire sole assembly 30, except for the bottom portion thereof, iscovered with plaster. Thereby, embodiment 30 is built into, and madeintegral to, the cast, but with the bottom surface of platform or sole43 and the bottom'surface of glide inserts 31-36 inclusive exposed andexternal of the cast, so as to be floor-engageable. In thisplatform-type or soletype embodiment 30 of the invention, as in the caseof the heel-type embodiments 10 and 20 shown in FIGS.

'1-3 inclusive, the individual wearer merely slides his cast-boundfooton the glide inserts, rather than lifting and then lowering hiscast-bound foot, as he would do if he were using a walking movement. Hemay elect,

however, to walk, rather than to use a sliding motion; and,additionally, he may remove the slide inserts, if such removal wouldassist him in walking. As a related matter, configuration of the glideinserts, although already discussed in part, will be further discussedin describing the modification shown in FIGS. As in the previousembodiments application of a predetermined pressure to the unit enablesretraction of the slides resulting in engagement of the frictionalmaterial with the floor.

Embodiment 50, FIGS. 6 and 7, which is in the form of an orthopedicshoe, may be used to encase a cast bound foot, or to encase an injuredfoot when normal walking would be too much strain. The individual slipsor inserts his foot, which may not be in a cast, into the shoe 50, FIG.6, through an appropriate opening and I retaining means, such as canvastop or uppers 53 havsult as in the previously described embodiments. Ifa 1 walking, rather than a sliding, movement is desired, the

glide inserts may be removed from the apparatus, such as 54-62inclusive, FIG. 6. As in the case of embodiment 30, FIGS. 4 and 5, theconfiguration of the glide inserts will be further discussed indescribing the modifications of FIG. 8.

Embodiments 80, FIG. 8, show various configuration of glide inserts 90and 100 and of the respective apertures 83 and 101 which may beadvantageously used in embodiment 30, the sole assembly, FIGS. 4 and 5,and in embodiment 50, the orthopedic shoe, FIGS. 6 and 7. In those twoaforementioned embodiments, it may be necessary for the wearers comfortto keep the glide insertion length short, or to have a very thickplatform or sole. Under these or similar circumstances, a glde insertand aperture configurated, respectively, as 90 and 83 and 100 and 101may be advisable to prevent the loss of a glide insert, although such aloss is so remote as to be unlikely. Nevertheless, at the risk of beingovercautious in the interest of the wearers safety, wide diameterportion 92 and 103 in the nature of a flange, of glide insert 90 andspring 102 insures positive retention and would alleviate anyapprehensions, real or otherwise, of the loss of a glide insertconfigurated as shown in FIGS. 1-7, inclusive. The embodiments of FIG. 8function as in all other described embodiments such that when weight isapplied the pressure on the glide causes it to withdraw within theaperture and allow for engagement with the retaining means with thefloor.

While there has been shown and described the fundamental features of ourinvention, as applied to particular embodiments, it is to be understoodthat this is by way of illustration only and is not intended as alimitation, and that various substitutions and omissions may be made bythose skilled in the art without departing from the spirit of theinvention. For example, although the glide inserts or second componentsof theassembly have been defined as having round shank portions, squareor any other regular shape could be utilized to provide for positivereinsertion of a glide within its similarly shaped aperture in the firstcomponent of the assembly to present a new wearing surface after theglide has achieved some wear in a first position. Also, the head portionneed not be of larger diameter. Only that portion of the glide tocontact the floor need be of material of low coefficient of friction.Thus, the configuration of the glide inserts, the number ofglide insertsused, the relative spacing from each other, the means by which they areretained, and the positioning of the glide inserts in the retainingmeans may be varied to provide a sliding movement which is mostbeneficial to the wearer of the embodiment, depending upon theparticular foot, ankle, and leg injury which resulted in the foot beingcast-bound. The retainer or first component could be made with acylindrical or other shaped rubber plug having aperture therein which isinserted and made fixed to the remainder of the retainer in order toprovide more easily the desired resiliency in the area around the glideor second component of the assembly. If desired, a backing material orplate may be provided to insulate the foot of a wearer from feelinglocalized pressure in the area above the glides. Additionally,embodiment 50, FIG. 7, could be in the form of a boot, a moccasin, aloafer, a slipper, and the like, rather than in the form of aconventional shoe.

What we claim is:

1. An assembly adapted for use with the foot of a human wearercomprising a first component which is of material of a high coefficientof friction to inhibit sliding when in contact with a floor, saidcomponent having at least one aperture therein;

a second component having a shank portion secured within an aperture ofsaid first component, and having a head portion providing a lowercoefficient of friction than that of said first component to permitsliding when in contact with a floor, said head portion protruding ashort distance from said first component; and

means responsive to a predetermined pressure applied to said secondcomponent to allow said second component to withdraw within said firstcomponent so as to protrude therefrom in order to allow for selectivecontact by the said first component with a floor.

2. An assembly as defined in claim 1 including means secured to saidfirst component for its attachment to the foot of a human wearer.

3. An assembly as defined in claim 1 wherein said last mentioned meansis a spring secured to both of said first and second components.

4. An assembly as defined in claim 1 wherein said last mentioned meanscomprises a section of resilient material around said aperture.

5. An assembly as defined in claim 1 wherein said head portion of saidsecond component has a ball bearing mounted therein to provide theprotrusion from said first component.

6. An assembly adapted for use with the foot of a human wearercomprising a first component which is of material of a high coefficientof friction to inhibit sliding when in contact with a floor and havingat least one portion having resiliency,

an aperture in said portion, and

a second component having a shank portion secured within said aperture,and having a head portion providing a lower coefficient of friction thanthat of said first component to permit sliding when in contact with afloor, said head protruding a short distance from said first component;

the resiliency of the resilient portion being such as to allow aretraction of said second component upon application of a predeterminedforce thereto.

1. An assembly adapted for use with the foot of a human wearercomprising a first component which is of material of a high coefficientof friction to inhibit sliding when in contact with a floor, saidcomponent having at least one aperture therein; a second componenthaving a shank portion secured within an aperture of said firstcomponent, and having a head portion providing a lower coefficient offriction than that of said first component to permit sliding when incontact with a floor, said head portion protruding a short distance fromsaid first component; and means responsive to a predetermined pressureapplied to said second component to allow said second component towithdraw within said first component so as not to protrude therefrom inorder to allow for selective contact by the said first component with afloor.
 2. An assembly as defined in claim 1 including means secured tosaid first component for its attachment to the foot of a human wearer.3. An assembly as defined in claim 1 wherein said last mentioned meansis a spring secured to both of said first and second components.
 4. Anassembly as defined in claim 1 wherein said last mentioned meanscomprises a section of resilient material around said aperture.
 5. Anassembly as defined in claim 1 wherein said head portion of said secondcomponent has a ball bearing mounted therein to provide the protrusionfrom said first component.
 6. An assembly adapted for use with the footof a human wearer comprising a first component which is of material of ahigh coefficient of friction to inhibit sliding when in contact with afloor and having at least one portion having resiliency, an aperture insaid portion, and a second component having a shank portion securedwithin said aperture, and having a head portion providing a lowercoefficient of friction than that of said first component to permitsliding when in contact with a floor, said head portion protruding ashort distance from said first component; the resiliency of theresilient portion being such as to allow a retraction of said secondcomponent upon application of a predetermined force thereto.